KR20050040456A - Oxy nitride layer forming apparatus - Google Patents

Abstract

An oxynitride film forming apparatus includes: a reactor for providing an oxynitride film processing space; A boat configured to be loaded and unloaded into and out of the reactor and to stack a plurality of wafers in multiple stages; A heater installed outside the reactor to provide a predetermined temperature atmosphere inside the reactor; A gas supply system installed at one side of the reactor to supply a reaction gas into the reactor; A preheater installed in the gas supply system for preheating the gas supplied into the reactor; And a gas exhaust machine installed at one side of the reactor to exhaust the reaction by-products generated while performing a predetermined process.

Description

Oxynitride film forming apparatus {OXY NITRIDE LAYER FORMING APPARATUS}

The present invention relates to an oxynitride film forming apparatus, and more particularly, to form an oxynitride film to thermally decompose a process gas injected during an oxidation process before being injected into a reaction chamber to solve a problem in which a process error occurs. Relates to a device.

In the process of manufacturing a semiconductor using silicon and various other silicon compounds to make an integrated circuit, in particular, a silicon oxide film (SiO ₂ ; hereinafter referred to as an oxide film) is an insulating layer for etching between devices, etching or ions. It is used in various applications such as a mask in an implantation process, a gate insulating film of a MOS transistor, a tunnel insulating film of a storage element, and an interlayer insulating film between multilayer wirings.

Such an oxide film can be formed by various methods. The methods are as follows.

First, there is a thermal oxidation method in which a silicon substrate is oxidized at a high temperature (800 ° C. to 1200 ° C.) in an oxygen atmosphere. The oxide film obtained by this method is used as a gate insulating film of a MOS transistor, a tunnel insulating film of a memory element, or the like.

Second, there is a chemical vapor deposition (CVD) method of atmospheric pressure or reduced pressure. This method uses a source of resistance heater or plasma as a heating source, such as source gas of silicon such as silane (SiH ₄ ), Teos (Tetra-ehtylortho Silicate), dichlorosilane (SiH ₂ Cl ₂ ) is decomposed at a relatively low temperature (200 ° C. to 850 ° C.) to form an oxynitride film. An interlayer insulating film of a multilayer wiring and a spacer of an LDD (Lightly Doped Drain) process, etc. Used as

Third, there is a method of uniformly applying liquid spin on glass (SOG) onto a silicon substrate with a spinner, and then forming an oxide film through a drying and annealing process. The oxide film obtained by this method is mainly used for the planarization process.

In recent years, as semiconductor devices have been increasingly integrated and accelerated, high quality, high reliability, and thin film formation are indispensable among the three oxide film forming methods described above, particularly in thermal oxide films used as gate oxide films of transistors and tunnel oxide films of memory devices. It becomes an element.

In detail, there are three methods of forming a thermal oxide film used in a semiconductor manufacturing process, such as a dry oxidation method, a wet oxidation method, and an HCl oxidation method. If you look like this: First, dry oxide films do not contain hydrogen bonds, so they have excellent resistance to hot carriers, while they contain a lot of oxygen defects that act as hole traps. This has a short disadvantage. On the other hand, wet and HCl oxides compensate for oxygen defects with hydrogen to reduce hole traps. have.

In order to overcome the above disadvantages, an oxidation method has been developed in which nitrogen is contained at the interface of the silicon substrate (Si) / oxide film (SiO ₂ ) to improve the reliability of the oxynitride film and prevent diffusion of impurities. This oxidation method forms a dry oxide film having a predetermined thickness, and then heats it in a rapid thermal processing (RTP) apparatus or an electric furnace using a gas such as NH ₃ , N ₂ O or NO, or N ₂ O together with oxygen in an electric furnace. By reacting, a nitrogen oxide is contained (hereinafter referred to as oxynitride film) in the Si / SiO ₂ system simultaneously with formation of a thermal oxide film.

Such an oxynitride film forming apparatus employs and employs a batch type reactor that mainly stores a plurality of wafers in a boat and processes them. In the case of such a batch type, a reaction gas is usually supplied from the upper side of the reactor, in which initial gas is introduced as the reaction gas at room temperature is supplied into the reactor heated to a high temperature atmosphere. Pyrolysis and exothermic reactions are relatively greater at the upper side of the reactor than the lower side, resulting in a difference in the concentration of the reaction gas for each region of the reactor. Therefore, there is a problem that it is difficult to form a uniform oxynitride film over the entire wafer.

Accordingly, the present invention has been made to solve the above-described problems, the object of the present invention is to pre-heat the reaction gas in advance before the reaction gas is supplied to the inside of the reactor by the thermal decomposition and exothermic reaction of the reaction gas uniform oxy An oxynitride film forming apparatus for achieving a nitride film forming condition is provided.

According to a first aspect of the present invention to achieve the above object, a reactor for providing an oxynitride film treatment space; A boat configured to be loaded and unloaded into and out of the reactor and to stack a plurality of wafers in multiple stages; A heater installed outside the reactor to provide a predetermined temperature atmosphere inside the reactor; A gas supply system installed at one side of the reactor to supply a reaction gas into the reactor; A preheater installed at the gas supply measurement to preheat the gas supplied into the reactor; And a gas exhaust system installed at one side of the reactor to exhaust the reaction by-products generated while performing a predetermined process.

The gas supply system includes an oxygen supply pipe through which oxygen gas is supplied, and a nitrogen supply pipe through which oxidative gas including nitrogen is supplied; The preheater is characterized in that installed in the nitrogen-based supply pipe.

According to a second aspect of the present invention, there is provided a process chamber for providing an oxynitride film processing space; A susceptor installed inside the processing chamber and on which a wafer on which an oxynitride film forming process is to be performed is mounted is mounted and performs a high temperature heating operation; A cover covering an upper side of the processing chamber; A shower head installed below the cover and configured to receive a predetermined reaction gas therein and to spray the reaction gas downward; A gas supply system supplying a predetermined reaction gas to the shower head; A preheating device installed at the gas supply measurement to preheat the reaction gas supplied to the shower head; And a gas exhaust system installed at one side of the processing chamber to exhaust the reaction by-products generated while performing the oxynitride film forming process.

The gas supply system includes an oxygen supply pipe through which oxygen gas is supplied, and a nitrogen supply pipe through which oxidative gas including nitrogen is supplied; The preheater is characterized in that installed in the nitrogen-based supply pipe.

Next, the structure and operation of the oxynitride film forming apparatus according to the present invention will be described in more detail with reference to FIGS. 1 and 2.

Example 1

1 is a view showing the configuration of a batch type oxynitride film forming apparatus according to an embodiment of the present invention, as shown in the reactor 10, heater 30, boat 50, elevator Means 70, gas supply system 90, gas exhaust system 110.

The reactor 10 is formed to have a predetermined oxynitride film forming space is formed in a long cylindrical shape in the vertical direction, to create a high-temperature atmosphere inside the reactor 10 on the outside of the reactor (10) The heater 30 is installed.

The boat 50 is provided with upper and lower support plates 51 and 53, and a plurality of struts 55 are arranged at predetermined intervals through the upper and lower support plates 51 and 53. In this case, a plurality of slots (not shown) may be provided in the support 55 so that a plurality of wafers W to form an oxynitride film may be stacked in multiple stages.

In addition, the boat 50 is vertically supported by the thermal insulation container 57, the thermal insulation container 57 is supported by the elevator means 70, the boat according to the up and down driving of the elevator means 70 50 is installed to be carried in and out of the reactor (10).

The gas supply system 90 includes an oxygen gas supply pipe 91 for flowing oxygen (O ₂ ) gas for oxidizing the wafer (W) and a nitrogen gas (eg, NO, N ₂ O, NO ₂ ). It consists of the nitrogen-based gas supply pipe 93 to supply. In this case, a plurality of nitrogen-based gas supply pipe 93 may be employed to supply the gas, respectively. On the other hand, the nitrogen-based gas supply pipe 93 is provided with a preheater 130 to preheat the nitrogen-based gas before being supplied into the reactor (10). The preheater 130 is pyrolysis and exothermic reaction in advance before entering the reactor 10 in order to prevent the gas at room temperature flows into the reactor 10 to form a high temperature atmosphere to cause rapid decomposition and exothermic reactions This is to prevent the formation of an unstable temperature atmosphere inside the reactor (10).

Next, the gas exhaust machine 110 exhausts the reactants generated during the oxynitride film forming process and also forms an exhaust pipe provided at the lower side of the reactor 10 to form the inside of the reactor 10 in a vacuum atmosphere. 111 and a vacuum pump 113 for providing a predetermined exhaust pumping force.

The following describes the operation principle of the oxynitride film forming apparatus configured as described above.

First, the heater 30 is operated to create the inside of the reactor 10 in a high temperature atmosphere, and then the elevator unit 70 operates the boat 50 on which the plurality of wafers W are loaded. I bring it in inside. Thereafter, while flowing dry oxygen gas through the oxygen supply gas pipe 91, the wafer W is heated to a high temperature to perform an oxidation treatment to form an oxide film.

Next, while evacuating the inside of the reactor 10 once while maintaining the wafer W at a predetermined temperature in the same reactor 10, the oxidizing gas (NO) containing nitrogen in the reactor 10 is again present. , N ₂ O, NO ₂ ) is converted into an oxynitride film by treating the oxide film.

As described above, the preheater 130 provided in the nitrogen-based gas supply pipe 93 while the nitrogen-based gas is supplied is heated before the gas is supplied into the reactor 10 to undergo a pyrolysis and exothermic reaction process. Thus, a rapid pyrolysis and exothermic reaction process occurs in the reactor 10 so that a uniform film can be formed by eliminating the temperature non-uniform atmosphere inside the reactor 10, especially the upper side.

Example 2

2 is a view showing the configuration of a single type oxynitride film forming apparatus according to another embodiment of the present invention. As shown in the drawing, a processing chamber 210, a susceptor 230, a lid 250, and a gas supply are provided. System 270, the gas exhaust machine 290.

The processing chamber 210 provides a predetermined oxynitride film formation space, and the susceptor 230 is installed on the inner bottom of the processing chamber 210 and supports the wafer W to be processed on the upper surface thereof. It is configured to be heated to a high temperature atmosphere.

The lid 250 is installed above the processing chamber 210 to cover the processing chamber 210, and the shower head 260 is installed at a bottom thereof. The shower head 260 stores a plurality of reaction holes (eg, one of oxygen, nitrogen monoxide, and nitrogen dioxide dinitrogen monoxide) in a plurality of injection holes 261 therein. ) Is provided.

The gas supply system 270 includes an oxygen gas supply pipe 271 for supplying the oxygen gas, and a nitrogen gas supply pipe 273 for supplying any one nitrogen gas of the nitrogen monoxide and nitrogen dioxide dinitrogen group. . At this time, the nitrogen-based gas supply pipe 273 is provided with a preheating device 310 to undergo a heat treatment process before the gas is supplied to the interior of the processing chamber 210.

The gas exhaust machine 290 exhausts the reactants generated during the oxynitride film forming process, and exhaust gas 291 provided at the lower side of the reactor 210 to form the inside of the reactor 210 in a vacuum atmosphere. ) And a vacuum pump 293 that provides a predetermined exhaust pumping force.

Next, the operation principle of the oxynitride film forming apparatus of the single type as described above will be described.

First, the wafer W is seated on the susceptor 230, and then the susceptor 230 is heated to a high temperature atmosphere. Thereafter, while drying oxygen gas flows through the oxygen gas supply pipe 271, the wafer W is heated to a high temperature to perform an oxidation treatment to form an oxide film.

Next, while vacuuming the inside of the processing chamber 210 once while maintaining the wafer W at a predetermined temperature in the same processing chamber 210, the oxidizing gas (NO) containing nitrogen in the processing chamber 210 again. , N ₂ 0, NO ₂ ) is converted into an oxynitride film by treating the oxide film while flowing the nitrogen-based gas supply pipe 273.

As described above, the preheater 310 provided in the nitrogen gas supply pipe 273 while the nitrogen gas is supplied is heated before the gas is supplied into the processing chamber 210 to undergo a pyrolysis and exothermic reaction process. Thus, a rapid thermal decomposition and exothermic reaction process occurs in the interior of the processing chamber 210, thereby eliminating a temperature non-uniform atmosphere inside the processing chamber 210 so that a uniform film can be formed.

As described above, in the formation of the oxynitride film, the reaction is performed by preheating the reaction gas (for example, nitrogen-based gas) supplied into the reaction space so that the reaction gas is supplied to the inside of the reaction chamber after undergoing an exothermic reaction and pyrolysis. There is an advantage in that the temperature atmosphere inside the chamber is made uniform to form a uniform oxynitride film.

As described above, in the detailed description of the present invention, specific embodiments have been described, but various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined by the claims below and equivalents thereof.

1 is a view showing the configuration of an arrangement type oxynitride film forming apparatus according to an embodiment of the present invention,

2 is a diagram showing the configuration of an arrangement type oxynitride film forming apparatus according to another embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

10: reaction chamber 30: heater

50: boat 70: elevator means

90,270 Gas supply system 91,271 Oxygen gas supply pipe

93,273: nitrogen gas supply pipe 110,290: gas exhaust machine

230: susceptor 260: shower head

Claims (4)

A reactor for providing an oxynitride film treatment space; A boat configured to be loaded and unloaded into and out of the reactor and to stack a plurality of wafers in multiple stages; A heater installed outside the reactor to provide a predetermined temperature atmosphere inside the reactor; A gas supply system installed at one side of the reactor to supply a reaction gas into the reactor; A preheater installed in the gas supply system for preheating the gas supplied into the reactor; And And a gas exhaust machine installed at one side of the reactor to exhaust the reaction by-products generated while performing a predetermined process. 2. The gas supply system according to claim 1, wherein the gas supply system includes an oxygen supply pipe through which oxygen gas is supplied, and a nitrogen supply pipe through which oxidative gas including nitrogen is supplied; And the preheater is installed in the nitrogen-based supply pipe. A processing chamber providing an oxynitride film processing space; A susceptor installed inside the processing chamber, and suspending the wafer on which the oxynitride film forming process is to be performed on the upper surface thereof to perform a high temperature heating operation; A lid covering an upper side of the processing chamber; A shower head installed below the cover and configured to receive a predetermined reaction gas therein and to spray the reaction gas downward; A gas supply system supplying a predetermined reaction gas to the shower head; A preheating device installed at the gas supply pipe side to preheat the reaction gas supplied to the shower head side; And And a gas exhaust machine installed at one side of the processing chamber to exhaust the reaction by-products generated while performing the oxynitride film forming process. 4. The gas supply system according to claim 3, wherein the gas supply system includes an oxygen supply pipe through which oxygen gas is supplied, and a nitrogen supply pipe through which oxidative gas including nitrogen is supplied; And the preheater is installed in the nitrogen-based supply pipe.